The second-year player was injured when he intercepted a pass in the end zone and attempted to run it out in the Packers' win over St. Louis on Oct. 16.

Shields didn't make it, taking a blindside hit from Rams receiver Brandon Gibson. The injury left Shields dizzy and stricken with headaches for a few days. He says it was his first concussion at any level of football.

Shields was cleared to practice after the Packers had their bye week. Even after the injury, the next time Shields intercepts a pass in the end zone might result in the same decision.

"You never know," he said. "We teach in our secondary group (that) whenever we catch the ball we're looking to 'pick six.' Every time we get our hands on the ball, we're trying to score. That's our mentality for our secondary on defense."

Following a slow start, Shields has been contributing with momentum-changing plays after he made an impact as an undrafted rookie last season with four interceptions, including two in the Packers' NFC Championship Game win at Chicago. Shields has two interceptions this season as the team's nickel back.